This invention relates to video signal processing methods and systems. More particularly, this invention relates to methods and systems for altering the content of video program material to expand or contract the total length of an entire program or program segment.
Video signal processing systems and methods are known for editing the content of an entire program or program segment in order to expand or contract the total program run time to match a desired run length or time segment. Frequently, a program or commercial which is scheduled for a predetermined broadcast time slot has a total running time which does not match exactly the time slot. In such cases, it is necessary to edit the program in order to fill the time slot exactly. In known systems, the program material must first be recorded on some suitable recording medium, such as magnetic tape, after which portions of the video program are deleted or repeated in order to contract or expand the running time to match the time slot. Such systems suffer from the disadvantage that the program to be edited cannot be simultaneously broadcast, but must be time delayed by the recording process. In addition, this technique is incompatible with live events, such as soccer matches, football games and the like, which must be broadcast and viewed substantially simultaneously. Efforts to date to provide real time video time editing to contract or expand the program length to match a desired run length have not met with success to date.
The invention comprises a method and system for providing real time video program expansion or contraction which relatively inexpensive to implement, easy to operate, and effective matching program run time with a predetermined run length. In addition, the invention is effective in creating surplus broadcast from any program in order to provide additional broadcast time for other information, such as commercial spots, public service announcements, and the like.
From a processing standpoint, the invention comprises a method of adjusting the total time length of a program having a fixed time duration by deleting or repeating individual frames or fields of video and audio segments on-the-fly, either on a fixed periodic basis, an automatic basis or manually using an operator controlled deletion or insertion circuit. The audio segments may or may not correspond to the frames or fields, but need only match the total time value of the deleted or repeated video frames or fields.
To contract a given program in the manual mode of operation, the operator monitors the video program material and deletes one frame or field at a time. A counter accumulates the time value of the sum of deleted frames or fields and displays this total to the operator. Once the desired amount of additional broadcast time has been accumulated, the original program material is permitted to be passed through unmodified. To expand a given program in the manual mode, the operator monitors the video program material and repeats one frame or field at a time, and the time accumulation counter keeps track of the total amount of time value of the repeated frames or fields and displays this information to the operator. Once the correct amount of time has been added to the original program material, the original program material is permitted to pass through unmodified. During the video deletion or repetition, corresponding segments of audio are deleted or repeated.
In the periodic mode of operation, the operator enters the total amount of time to be deleted or added to the original program material length, and frames or fields and corresponding audio segments are deleted or added automatically in a periodic manner, e.g. one frame every five frames, one field every five fields, etc. The time counter accumulates the running total of deleted or added time, and terminates the deletion or insertion process when the running total equals the preselected amount.
In the automatic mode of operation, the operator adds the total amount of time to be deleted or added to the original program material length, and frames or fields and audio segments are deleted or added automatically, with the choice of particular frames/fields and audio segments being determined by video motion detectors and audio pitch and level detectors, so that optimal deletion or insertion is effected.
In both the periodic and automatic modes of operation, an optional pause function protects any specially selected sensitive programming material from being affected by the time change processing. The pause function itself may be manually controlled by an operator, or automatically performed by detecting special marker information inserted in predetermined frames/fields, or in reserved portions of same (i.e. during vertical blanking).
The invention enables on-the-fly adjustment of the running time of program material without affecting the actual broadcast of the program material. In addition, for programs of indeterminate length, the invention enables a fixed amount of time to be added or deleted over a preselected time period. For example, the invention can be used to gain a preselected fixed amount of timexe2x80x94e.g. ten minutes over a one hour broadcast time periodxe2x80x94using either the manual or periodic modes of operation. Most importantly, the time deletion or insertion does not visibly affect the program content as experienced by the viewer, so that the program material can be enjoyed to the same extent as the original program material.
For a fuller understanding of the nature and advantages of the invention reference should be made to the ensuing detailed description of the invention, taken in conjunction smith the accompanying drawings.